Studies of Nano-sized Co3O4 as Anode Materials for Lithium-ion Batteries

The structural evolution of the Co 3O 4 fine powders prepared by rheological phase reaction and pyrolysis method upon different temperature has been investigated using X ray diffraction (XRD) topography. The electrochemical performance of Co 3O 4 electrode materials for Li ion batteries is studied in the form of Li/Co 3O 4 cells. The reversible capacity as high as 930 mAh/g for the Co 3O 4 sample heat treated at 600 ℃ is achieved and sustained over 30 times charge discharge cycles at room temperature. The detailed information concerning the reaction mechanism of Co 3O 4 active material together with lithium ion is obtained through ex situ XRD topography, X ray photoelectron spectroscopy (XPS) analysis and cyclic voltammetry (CV) technique. And it is revealed that a “two step” reaction is involved in the charge and discharge of the Li/Co 3O 4 cells, in which Co 3O 4 active material is reversibly reduced into x Co· (3- x )CoO and then into metallic Co.